1. Field of the Invention
The present invention relates to a hand-held ophthalmological apparatus, including a hand unit held by a measurer, for observing or measuring an examinee's eye.
2. Related Background Art
As illustrated in FIG. 6, e.g., a tabletop eye refracting power measuring apparatus may be considered conventional ophthalmological apparatus.
This eye refracting power measuring apparatus is constructed of a base 8 and a slide pedestal 6 so mounted as to be movable in back-and-forth/right-and-left directions with respect to this base 8. This measuring apparatus is also constructed of a measuring unit 5 equipped with a variety of optical members and so mounted as to be movable in up-and-down directions with respect to the slide pedestal 6 and a support unit 9 for supporting the head of an examinee 1. The support unit 9 has a forehead contact member 9a, a jaw supporter 9b and a support rod 9c through which these components are linked to the base 8.
In the case of using this eye refracting power measuring apparatus, at first, a jaw of the examinee 1 is placed on the jaw supporter 9b, and a forehead 3 of the examinee 1 is brought into contact with the forehead contact member 9a. Then, the head of the examinee 1 is fixed with respect to the base 8. Subsequently, the measuring unit 5 is moved by operating an operation handle 7 provided on the slide pedestal 6 so that an optical axis C of the measuring unit 5 is set coaxial with an optical axis of the examinee's eye 2. Thereafter, the measurer makes a predetermined measurement while seeing through the optical system or watching a monitor.
A small-sized hand-held eye refracting power measuring apparatus has been offered in recent years in response to a demand for measuring the eye refracting power during a variety of operations. This eye refracting power measuring apparatus includes a measuring optical system for one eye and a hand unit fixed thereto. This type of hand-held eye refracting power measuring apparatus unlike the tabletop type, is not provided with the base, the slide pedestal and the support unit to allow it to be portable in order to examine the examinee's eye in every state as in the case of, e.g., an operation or the like.
According to such a conventional hand-held ophthalmological apparatus, however, as explained above, the measurer having this apparatus is incapable of maintaining a mutual positional relationship between the examinee's eye and the measuring unit during the measurement as a result of emphasizing the portability, resulting in such a problem that a satisfactory measurement can not be performed.